Joseph nodder



UNITED STATES ATENT OFFICE.

.IOSEPII NODDER, OF SHEFFIELD, ENGLAND, ASSIGNOR TO THE JOI-IN BROWN tCOMPANY, LIMITED, OF SAME PLACE.

STEAM-BOILER FURNACE AND FLUE.

SPECIFICATION forming part of Letters Patent No. 574,107, dated December29, 1896.

Application led August 20, 1896.` Serial No. 803,400. (No model.)

The plates of which the said boiler furnacesV or iiues are made are ofunequal thickness, the thicker portions being constituted by hollow ribsarrangedtransversely to the axis of the furnace or flue, the con cavitybeing on the fire side of the furnace or flue and the conveXity on thewater side, the tops of the said ribs being thicker than the otherportions of the plate. Between the ribs thus formed arched parts orportions are made with a sweeping curve, the convexity thereof being onthe water side and the concavity on the fire side, these curved partspreferably joining the ribs aforesaid by reversely-curved portions.

The accompanying drawing represents in longit-udinal section a portionof a boiler furnace or iue sufficient to illustrate this invention.

A are the aforesaid thickened hollow ribs arranged transversely to theaxis of the furnace or flue. These have a concavity on the fire side ata, the top or convexity a2 being on the water side of the furnace orflue.

.B are the arched parts or portions between the ribs A, these saidarched parts or portions being made with a sweeping curve, with theconcavity b on the fire side and the convexity b2 on the water side ofthe furnace or flue, the said parts B joining the ribs A byreversely-curved portions, as at c.

It has been practically demonstrated that furnace-fines having noprovision for longitudinal movement caused by expansion and contractionduring work are particularly liable to circumferential splits at thebase of the rib, while iues of the corrugated and suspension arch typeelongate too easily, and when compelled to contract by the cooling ofthe boiler do not retain their circularity, but are' forced inward andpartially collapsed.

Vith the form of flue constituting the present invention the circularityof the iiue is maintained by the thickened ribs or bands, while thearches and curved parts at the end of the arched parts providesufficient flexibility for contraction and elongation, so that even withincreased strength against collapse I avoid the longitudinal rigidity offlues having no provision for longitudinal movement caused by expansionand contraction during work and the longitudinal weakness of thecorrugated and suspension arch flues without further encroachment on thewater-space of the boiler, the space inclosed between two parallel linesfrom fire to water being less than in any other furnace-iiue of thisclass known to me.

My furnace-flue has been demonstrated to 'thereof on the iire side ofthe iiue, substantially as described.

2. A boiler furnace or iiue having thickened hollow ribs, archedportions between the ribs, the convexities of said parts being on thewater side of the flue and the concavities thereof on the fire side ofthe flue, curved portions intermediate of and connecting the archedportions to the ribs, substantially as described.

In testimony whereof I have signed my name to this speciiication in thepresence of two subscribing witnesses.

JOSEPH NODDER. Witnesses:

OHAs. MAXEY, J. E. ToWNsEND.

